Interdental toothbrush



FIG. 1 is a front perspective view of an interdental toothbrush showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines in the drawings depict portions of the interdental toothbrush that form no part of the claimed design. 

CLAIM The ornamental design for an interdental toothbrush, as shown and described. 